This document summarizes a study comparing liquid dairy manure application methods in terms of ammonia emission, odor emission, and costs. Researchers conducted on-farm trials applying manure via surface broadcast or deep injection. Results showed subsurface injection reduced odor and ammonia emissions by up to 82% and 64% respectively compared to surface application. While subsurface injection had higher estimated costs, these may be offset by higher nitrogen value captured in the soil. In conclusion, subsurface injection was recommended as a best practice to control emissions.

1. On-Farm Comparison of Two Liquid
Dairy Manure Application Methods in
Terms of Ammonia Emission, Odor
Emission, and Costs
L. Chen, M. de Haro Marti, W. Gray, H. Neibling,
M. Chahine, and S. K. R. Yadanaparthi.
From Waste to Worth Conference
Denver, Colorado
April 3rd, 2013

2. Outline
 Introduction
 Objective
 What we did
 Results
 Summary
 Acknowledgements

3. Introduction
 Dairy production stands as the single largest agricultural pursuit
in Idaho. Currently, Idaho is the third largest milk production
state in the US.
 A number of dairies in Magic Valley use flushing systems
resulting in a huge amount of lagoon water which is applied to
crop land via irrigation systems.
 The volatilization of ammonia from irrigated lands is not only a
loss of valuable N, but also cause air pollution.

4. Introduction
 Concentrated dairy production in a limited area such as the
Magic Valley has caused air and water quality concerns.
 Manure direct injection has been proven in other regions to
effectively manage odors and manure nutrients.

5. Objective
 The purpose of this project was to demonstrate, evaluate, and
encourage the widespread adoption of the manure direct
injection method in southern Idaho for mitigating odor and
ammonia emissions.

6. What we did
 A manure application field day was held on a
dairy in Buhl, Idaho.

7. What we did
 On-farm manure application trials conducted at
two sites were comprised of two manure
application methods: surface broadcast and
deep injection.

8. What we did
 At each of the sites, a square plot of about 3,600 m2
(200 X 200 ft) was used for surface broadcast.
200 m
1.5 m towers
Passive NH3 sampler
Soil temperature probes
with a data logger

9. What we did
 Passive NH3 samplers were used to determine the NH3
concentration at each location. Ammonia samplers were
changed approximately every 24 hours over a two-day period.
 Air samples were collected from test site 1 for odor evaluation.
 For each test site, one liter of liquid manure was collected for
pH and total nitrogen analysis.

10. What we did
 A soil temperature probe with a data logger was used to record
soil temperature data in 15-min increments.
 Weather data were obtained from local Buhl Airport.
 Cost analysis was carried out for four different manure land
application systems.

11. Results
Table 1. manure pH and total N concentrations and application rates of total N at the two test sites
Site and Application Method Manure pH
Manure total N
concentration (mg/L)
Manure Total N
Application Rate (kg/acre)
Site 1 7.4 3433 257
Site 2 7.3 3519 265
Table 2. Ambient weather conditions and soil temperature at the test sites
Site 1 Site 2
Item Day 1 Day 2 Day 1 Day 2
Average wind speed, m/s 5.0 4.2 4.2 3.1
Air temperature, average(minimum, maximum),
˚F
61 (42, 78) 49 (45, 63) 49 (45, 63) 47 (38, 61)
Average relative humidity, % 28 53 53 51
Soil temperature, average(minimum, maximum),
˚F
50.9 (51.1, 56.1) 47.3 (51.1, 51.2) 46.5 (51.5, 52.1) 66.7 (51.6, 69.1)

12. Results
0
20
40
60
80
100
120
Background Subsurface Injection Surface Broadcast
OdorDetectionThreshold(OU/m3)
Sampling Location
Odor Results
Odor concentration: 44 OU/m3 (background),
61 OU/m3 (injection),
92 OU/m3 (surface broadcast).

13. Results
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Broadcast Injection Background
Ammonia(mgofNH3-N/m3)
Sampling location
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Broadcast Injection Background
Ammonia(mgofNH3-N/m3)
Sampling location
First day from test site 1 Second day from test site 1
The NH3 data from test site 1 showed 82% and 64% reduction in NH3
concentration for first and second sampling days, respectively when
liquid manure was applied by subsurface injection vs. surface broadcast.

14. Results
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Broadcast Injection Background
Ammonia(mgofNH3-N/m3)
Sampling location
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Broadcast Injection Background
Ammonia(mgofNH3-N/m3)
Sampling location
First day from test site 2 Second day from test site 2
The NH3 data showed 64% and 41% reduction in NH3 concentration for
first and second sampling days, respectively when liquid manure was
applied by subsurface injection compared with surface broadcast.

15. Results
Manure applicaiton system Total Cost ($/acre)
Tank system with broadcasting $22.20*
Tank injection using disk injection $29.89*
Tank injection using knife injection $30.74*
Drag hose system with knife injection $67.48
*Time and equipment to refill the tank is not included in these calculations.
The subsurface injection method has higher costs mainly due to the
need of larger tractor and lower operating speed.

16. Summary
 Subsurface injection can reduce both the odor and NH3 emissions
compared with surface broadcast; therefore, applying liquid dairy
manure by subsurface injection could be recommended as one of
the best management practices to control NH3 and odor emissions.
 The estimated costs associated with subsurface injection were
higher than surface broadcast. However, the higher costs could be
compensated by the higher nitrogen fertilizer value captured in the
soil by the subsurface injection method.

17. Acknowledgements
This project was supported by the USDA Natural Resources
Conservation Service through a Conservation Innovation
Grant.
We would also like to thank Dr. April Leytem and Mr. Myles
Miller (USDA Northwest Irrigation and Soils Research
laboratory (NWISRL) for their help with analysis of ammonia
samples.

18. Thanks!
Questions?